Implant passageway

ABSTRACT

Implant passageway for connection of body cavities, vessels or other organs to a device, container, pump or the like externally of the body, forming a tunnel and/or canal network inwardly of a smooth end portion for fixation and integration of the implant in the surrounding tissue.

TECHNICAL FIELD

The invention relates to an element for controlled growth of tissue intosurgically intervened regions, e.g. for implant passageways, such anelement being used to fix a prosthesis in the body or forming such aprosthetis itself.

BACKGROUND OF THE INVENTION

When an element is to be incorporated into a tissue or is to beimplanted in such a way that it must pass through several tissues, i.e.in case of through the skin or through a mucous membrane, it is requiredthat the element should be biocompatible, i.e. it must be accepted bythe tissue, and the problem arises how to achieve a reliable retentionof the element in the surrounding tissue to avoid a purely mechanicaldislocation of the element. Unsatisfactory biocompatibility as well asinsufficient retention leads to tissue irritation, possibly followed bytissue rupture at the element. This means formation of reactive zones ofconnective tissue with a more or less pronounced streak of inflammationleading to the element no longer being harmoniously incorporated in thetissue region; the element starts to wander and loses its function.Furthermore, tissue irritation at implant passageways leads todowngrowth of epithelium around the element and, as a consequencethereof, finally to rejection.

In order to solve these problems, the element according to the inventionhas obtained the characteristics of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For explanation of the invention in more detail reference is made to theaccompanying drawings, wherein

FIG. 1 shows a cylindrical implant element having peripheral grooves anda central passage,

FIG. 2 illustrates an outer socket having through holes of the samelevels as the grooves of the cylinder of FIG. 1,

FIG. 3 shows the cylinder and tee socket pressed together to form a unitproviding a tunnel and/or canal network within the periphery of theimplant element, and

FIG. 4 is an illustration similar to FIG. 3 but with a diametricallywider flange on the upper end portion of the cylinder.

DETAILED DESCRIPTION

In the illustrated embodiment, the element 10 is tubular and cancomprise e.g. an implanted conduit for peritoneal dialysis (abdominaldialysis). The conduit can be rigid or flexible. It forms a number oftunnel and/or canal networks 11, which are separated from the passage 12through the element by a solid wall 13 and from the exterior surface ofthe element by an ingrowth zone 14, the openings of which are indicatedat 15 and form circular apertures. The connective tissue, which isindicated at 16, grows into the tunnel and/or canal network 11, maturesand attains a structural organization resulting in the epithelium 17being prevented from growing down along the surface of the element andinfiltrating the layer of connective tissue next to the element toenclose eventually the element 10, which leads to rejection of theelement. The tissue ingrowth into the tunnel and/or canal network 11should be such that the connective tissue inside the tunnel and/or canalnetwork 11 becomes complete and attains full maturity, i.e. the tunneland/or canal network 11 should be sufficiently large to allow theconnective tissue cells as well as the blood-vessels necessary for themaintenance of the connective tissue to grow thereinto, thus creatingconditions for the generation of connective tissue fibres and matrix bythe connective tissue cells and for the maturation of the components ofthe connective tissue and normal renewal thereof, requiring that no partof the tunnel and/or canal network 11 should have a diameter less than30 μm.

According to the invention, the surfaces of the element 10, which areexposed to the surrounding tissue, consist of a biocompatible material,titanium being an excellent material of this kind. The element 10 as awhole can consist of titanium, but preferably the element 10 is coatedon said surfaces, i.e. the exterior surface of the element inside thetunnel and/or canal network il, with titanium by a thin layer thereofbeing deposited on a substrate by vacuum evaporation. This substrate canbe rigid or flexible and can consist of e.g. silicone rubber, polyesteror polytetrafluoro ethylene. In the illustrated embodiment, the openings15 of the tunnel and/or canal network have sharp edges, but the edgescan be formed in another way, e.g. as beveled edges on the outside ofthe element or inside the tunnel and/or canal network 11, or they can berounded.

When an implant passageway is implanted in the body tissue in the waywhich has been described, the connective tissue has the opportunity tomature adjacent to the surface of the element 10 and inside the tunneland/or canal network 11 in order to achieve a reliable and permanentretention of the element by preventing the epithelium from growing downaround the element at the implant passageway.

The portion of the surface of the element 10, located immediately abovethe uppermost tunnel and/or canal opening 11 provided in the wall of theelement, which is exposed to the epithelium layer 17, therefore shouldbe suitably profiled. e.g. widened as in FIG. 4. This arrangementfurther prevents downgrowth of epithelium along the surface of theelement during the time required for the granulation tissue of the woundregion to mature into a firm, structured connective tissue.

The tunnel and/or canal network 11 can be constructed in severaldifferent ways, e.g. as a labyrinth system.

What is claimed is:
 1. Implant passageway for connection of bodycavities, vessels and other organs to a device externally of the body,having a biocompatible surface and comprising a tubular element forminga through passage and peripheral grooves on the outside of the curvedsurface thereof inwardly of an end portion having a smooth surface, anda socket surrounding the tubular element and forming through holes inregister with said grooves and together with the tubular elementdefining a number of passage networks with a minimum cross-sectionaldimension of 30 μm for controlled growth of surrounding tissue thereintoin order to prevent epothelium from growing down around the passagewayand achieve a reliable and permanent retention thereof.
 2. Implantpassageway as in claim 1 wherein said end portion of the element iswidened in relation to the remaining portion of the element.